I noticed yesterday that my dwarf cichlid wasnt eating, I thought it was because the platy's were getting to the food before he could so I decided to monitor him for the weekend and if he still wasn't move him to a slightly smaller tank with only two other fish in. This morning he was fine, I just checked on him again as I went to feed them and he has a open wound where his anal hole is he was swimming at the top of the tank. I have added some melafix to the tank and I have just seen him sifting for food at the bottom of the tank. Any ideas what may have caused this and if he has any chance of survival? The tank is 180L, water perameters are all fine there are about there are 20 fish in the tank (10 platy's, 8 Danios, my dwarf cichlid and a peaceful Betta.) I feed them a mix of pellets, flakes, gel food, frozen food and veg. Not all in the same day they have a feeding Rota of what they have on what day. I feed them twice a day morning and night and I do a 25% water change once a week, then once a month I do it two days in a row for a 50% water change.

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has this about wounds

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SoresDefinition Red sores are best diagnosed by knowing the fish's history. If the fish has suffered trauma the red sores are actual wounds, but if the sores slowly appear they are likely caused by bacteria and are developing ulcers. Redness in the mouth area is probably flex.

Causes and TreatmentUlcers Red sores on the body are often signs of a bacterial infection and ulcers. The bacteria that causes these sores is often Aeromonas hydrophila. This type of infection is often secondary to fluke infestation, so we recommend treating for flukes as well as addressing the sores directly. It is important to isolate the fish in a hospital tank. You can treat topically as explained here and combine this treatment with feeding of medicated food. Medi-Gold and MediKoi are the best choices for treating this kind of infection. If there is a white center developing, it is clearly infected and may be ulcerating. The fish may need to be injected with an antibiotic, or if that is not possible treated in a bath of Tricide Neo (sometimes sold as Neocide 3).This is a serious illness, but treatable, so please post in our forum so we can help you more specifically.

Cuts and Scrapes If the sore is the result of an injury, the best thing to do is to keep the water clean and feed good food so that the fish will nicely recover on his own. The sore can be swabbed one time with Iodine or 3% hydrogen peroxide. Additional swabs will kill the new, healthy cells growing in. If the fish has suffered some trauma and is bleeding, pressure can be applied to the wound to stop the bleeding. You may want to sedate the fish first as described here.

Maybe just have a think, look around the tank if it was possible for the cichlid to have caught itself somewhere or if another fish is the culprit?

Thank you. What can cause a nitrate spike? I said that my peramiters were fine because I had tested them recently, I thought it had only been a few days but when I sat down to think about it it had been just over a week so I tested again, my nitrites were fine and my ammonia was up a tiny amount but not much 0.25 ppm, but my nitrates were at 20ppm! I don't know how this has happened. I have since done a couple of 25% water changes (3 in 3days) and the level has dropped slightly. All my other fish seem fine and happy.

Nitrates are generally okay as long as their below 40ppm (assuming its the same for tropical's as it is for goldfish).

I think generally a rise in Nitrates would be down to extra leftover waste or excrement from the fish being converted by the bacteria? Perhaps there was some waste that the bacteria couldn't cope with, hence the low ammonia reading?

Just make sure you don't over feed, left over food can often be a culprit or a dead fish that hasn't been removed (don't think that's the case here though) and of course the weekly gravel clean to get rid of the muck How often do you clean the filter? Could be a build up of waste in there? Or a build up of something in the pipes? (<- this would be for external filters only, I forget what you have)